[perl #42463] Subtraction of numbers

# New Ticket Created by  sayd@bug.botik.ru 
# Please include the string:  [perl #42463]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=42463 >



This is a bug report for perl from sayd@bug.botik.ru,
generated with the help of perlbug 1.35 running under perl v5.8.8.


-----------------------------------------------------------------
I have following:

# perl -le 'print 12.69-12.16'
0.529999999999999

# perl -le 'print 19.69-19.16'
0.530000000000001

It has forced me to use:
$var = 19.69 - 19.16;
$var = printf ("%.2f", $var);

-----------------------------------------------------------------
---
Flags:
    category=core
    severity=medium
---
Site configuration information for perl v5.8.8:

Configured by Debian Project at Wed Dec  6 23:17:41 UTC 2006.

Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=linux, osvers=2.6.18.3, archname=i486-linux-gnu-thread-multi
    uname='linux saens 2.6.18.3 #1 smp sat nov 25 13:39:52 est 2006 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8 -Darchlib=/usr/lib/perl/5.8 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.8 -Dsitearch=/usr/local/lib/perl/5.8.8 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.8 -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define usemultiplicity=define
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.1.2 20061115 (prerelease) (Debian 4.1.1-20)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/libc-2.3.6.so, so=so, useshrplib=true, libperl=libperl.so.5.8.8
    gnulibc_version='2.3.6'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    

---
@INC for perl v5.8.8:
    /etc/perl
    /usr/local/lib/perl/5.8.8
    /usr/local/share/perl/5.8.8
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.8
    /usr/share/perl/5.8
    /usr/local/lib/site_perl
    .

---
Environment for perl v5.8.8:
    HOME=/home/sayd
    LANG=C
    LANGUAGE (unset)
    LC_CTYPE=ru_RU.KOI8-R
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/usr/local/sbin:/usr/sbin:/sbin:/usr/src/l2j/jre1.5.0_06/:/usr/local/bin:/usr/games:/usr/X11R6/bin:/usr/bin:/bin:/usr/sbin:/usr/lib/games/quake2:/usr/lib/locate/:/home/sayd/.rshell:/home/sayd/vicq
    PERL_BADLANG (unset)
    SHELL=/usr/bin/tcsh

• [perl #42463] Subtraction of numbers by sayd @ bug . botik . ru
• Re: [perl #42463] Subtraction of numbers by Rafael Garcia-Suarez
• Re: [perl #42463] Subtraction of numbers by Dominic Dunlop